Vehicle speed control system

Abstract

A vehicle speed control system for a vehicle having a plurality of wheels, the vehicle speed control system comprising one or more electronic control units configured to carry out a method that includes applying torque to at least one of the plurality of wheels, detecting a slip event between any one or more of the wheels and the ground over which the vehicle is travelling when the vehicle is in motion and providing a slip detection output signal in the event thereof. The method carried out by the one or more electronic control units further includes receiving a user input of a target speed at which the vehicle is intended to travel and maintaining the vehicle at the target speed independently of the slip detection output signal by adjusting the amount of torque applied to the at least one of the plurality of wheels.

Description

FIELD OF THE INVENTION[0001]The invention relates to a system for controlling the speed of a vehicle. In particular, but not exclusively, the invention relates to a system for controlling the speed of a land-based vehicle which is capable of driving in a variety of different and extreme terrains and conditions.BACKGROUND TO THE INVENTION[0002]In known vehicle speed control systems, typically referred to as cruise control systems, the vehicle speed is maintained once set by the user without further intervention by the user so as to improve the driving experience for the user.[0003]The user selects a speed at which the vehicle is to be maintained, and the vehicle is maintained at that speed for as long as the user does not apply a brake or, in some systems, the clutch. The cruise control system takes its speed signal from the driveshaft or wheel speed sensors. When the brake or the clutch is depressed, the cruise control system is disabled so that the user can change the vehicle speed...

AI Technical Summary

Benefits of technology

The invention allows the user to control the speed of a vehicle without having to use the pedals. This is useful when the vehicle is moving on terrain that is slippery or icy. The user doesn't have to worry about regulating the speed, which makes it easier for them to focus on other parts of navigation, such as planning a route or avoiding obstacles. This is especially helpful when the vehicle is driving through deep water or on off-road terrains.

Problems solved by technology

In congested traffic conditions, however, where vehicle speed tends to vary widely, cruise control systems are ineffective, and especially where the systems are inoperable because of a minimum speed requirement.

Such systems are therefore ineffective in certain driving conditions (e.g. low speed) and are set to be automatically disabled in circumstances in which a user may not consider it to be desirable to do so.

A problem with existing vehicle speed control systems, such as cruise control systems, is that the system is cancelled when the vehicle detects a wheel slip event at one or more wheel.

Whilst the approach taken by known cruise control systems may be entirely appropriate for driving on the highway, it makes these ‘on-highway’ cruise control systems unreliable and entirely inappropriate for use in most off-road driving applications, where the driving speed is typically much lower and the varied nature of the terrain tends to give rise to frequent slip events.

In other words, driving in adverse and slippery conditions off-road, where wheel slip is not uncommon, on-highway cruise control systems are ineffective.

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